A STUDY OF THE DISTRIBUTION OF THE ANNUAL EXTREME DAILY PRECIPITATION TOTALS IN ATHENS, GREECE

The objective of the study is to investigate the probability distribution function of the annual extreme daily precipitation totals over Athens province. In particular, the series of annual extreme daily precipitation totals at the National Observatory of Athens, for a 115-years period (1891-2005), is analyzed in order to define the appropriate probability distribution model. The candidate distributions are the 3-parameter Gamma distribution and the Generalized Extreme Value (GEV) or Jenkinson's distribution. The various parameters of candidate distributions are estimated with the method of maximum likelihood, the method of moment estimator and the probability-weighted method. Chi-squared test is utilized for testing the fit of the two candidate distributions to the sample. The 3-parameter Gamma distribution is rejected, and several validation methods are utilized in order to decide whether the Gumbel or the Frechet distribution fits better to the data.